1. Field of Invention
This invention relates to exporting power in a renewable energy system employing a battery charger, and more particularly to effecting a charge sequence in such system, wherein adherence to the charge sequence determines the amount of power to be exported.
2. Description of Related Art
Because electrical utility service can sometimes fail, it may be desirable to equip a home or other electrical utility usage site with a source of backup electrical power. The source of backup electrical power may be one or more batteries, such as lead acid batteries, for example.
In some systems, a renewable energy source, such as a photovoltaic panel or array for example, may be used to charge the batteries. In these systems, the renewable energy source may generate more energy than is required to charge the batteries, and therefore some of the generated energy may be exported to the electrical utility service, potentially reducing a user's electrical utility charges.
However, it has been found that these systems may export energy to the electrical utility service in a manner that does not enable a battery charger to apply preferable charge cycles to the batteries. The charge cycles applied to batteries in some backup electrical power systems may, for example, lead to accelerated corrosion or sulfation of plates in the batteries, and may result in premature loss of electrolytes in the batteries.